Apparatus for conditioning and agitating pulps



Feb. 7, 1939. A A. c. DAMAN ,5

' APPARATUS FOR CONDITIONING AND AGITATING PULPS Filed May 5, 1936 iilIIIllIIlIII 4 5 INVENTOR.

w 1 ORNEY.

Patented Feb. 7, 1939 APPARATUS FOR CONDITIONING AND AGITATING PULPS Arthur C. Daman, Denver, (1010., assignor, by

mesne assignments, to Mining Process and Patent Company, a. corporation of Delaware Application May 5, 1936, Serial No. 17,940

15 Claims. (01. 261 -77) This invention relates to improvements in agitators and conditioners and to methods of agitating and conditioning pulps, and its primary object is to provide a method and means for maintaining substantially all the constituent ore particles of a pulp in suspension while such particles are being subjected tothe action of one or more reagents and/or aeration.

Another object of theinvention resides in the provision of mechanical agitators cooperating with air lifts for inducing a circulatory movement of 'solids in liquid suspension through the apparatus.

A further object of the invention is to provide apparatus for agitating or conditioning materials which is simple, durable and eiiicient, and which may be readily adapted for a wide variety of treatments. 7

A still further object of the invention is the provision of an elevating mechanism for raising and lowering the agitator elements to prevent overloading following shut downs and the like.

Other objects reside in novel details of construction and novel combinations and arrangements of parts, as well as novel steps and processes, all of which will more fully appear in the course of the following description.

In order to promote a better understanding of the invention, reference will now be made to the accompanying drawing in the several views of which like parts have been similarly designated, and in which;

Figure 1 represents a plan view of a conditioner embodying the present invention,

Figure 2 is a section taken along the line 22, Figure 1,

- Figure 3 is an enlarged fragmentary view, partially in section, showing details of the stirrer or 1 agitator construction, and

Figure 4 is an enlarged fragmentary section of the air admission control of a. conditioning element.

In the drawing, the reference numeral 5 indicates a tank, provided at 6 with an overflow determining a liquid level in the tank. As illustrated, the overflow is in the form of a discharge orifice, but if desired, an adjustable weir or other regulatable discharge may be'employed within the scope of the invention.

A suitable superstructure I is provided at the top of tank 5, and one or more conditioning ele- 'ments orunits are suspended from the superstructure within the tank. These units each comprise a hollow body or casing 8 extending from an elevation above the liquid level in the tank to an elevation below the same, and terminating at the lower elevation in a flaring portion 9 having a restricted communication with the interior passage thru the rest of the body.

,The flaring portion acts as a housing or shield 5 for a rotary impeller I!) carried on a shaft [2 journaled on superstructure I, which shaft carries at its end outside the tank 5, a pulley l3 connected by a belt I 4 with a motor l5 mounted on the superstructure. 0

A branch conduit i6 leads into a side of casing 8 from an elevation above the liquid level in tank 5 and is the feed inlet of the unit. Feed to the tank may be introduced thru an inlet 43, or if preferred, may be introduced directly into the 15 tank 5. Adjacent the point of entrance of conduit IS, the casing is apertured for the admission of supernatant matter and/or air, as indicated at H, the said aperture being at the approximate overflow elevation, and preferably 20 slightly above the same.

The tank 5 is apertured ati8 adjacent its bottom to receive a nipple I9 connecting with an elevating conduit 20 which acts as an air-lift of the type shown and described in U. S. Letters 25 Patent of H. V. Wallace et al., No. 2,077,445. Air under pressure is d scharged into conduit 20 thru pipe 2|, and is efiective for raising pulp flowing into the conduit 20 thru the nipple 2| to a discharge 22 atan elevation above the liquid'level 30 in tank 5.

It is sometimes preferable to locate the air-. lift within the tank 5, and an upwardly-ranging conduit 20a is disposed in the tankwith an open end spaced from, but adjacent the .bottom of 35 the tank. An air pipe Zla extends thru the. conduit 20a and terminates in its lower portion, discharging downwardly, as shown in Figure 2. The conduit 20a. is provided with a discharge outlet 22a, similar to outlet 22. 4

Conduits 23 receive the discharge thru outlets 22 and 22a and direct the same into tank 5. A portion of the material in conduit 23 is normally intercepted by branch conduit [6, and this material becomes the feed of the conditioner 45 units. The material not admitted to branch is flows into the tank thru a plurality of openings 32 as indicated by the arrows in Figure"'1.

In order to permit regulation of the feed to the conditioner units, valves 33 and 3311. are provided, which permit any selective amount of material in conduit 23 to be directed thru branch IE, or if desired, all said material can be discharged directly into tank 5.

A rotary stirrer or agitator 24 is suspended 55.

adjacent the bottom of tank 5 to maintain the solids in the pulp in a state of suspension, and to aid the movement of material thru apertures l9 or into conduit 20a. The agitator 24 is carried on a shaft 25- journaled on superstructure l. A gear 26 on the upper end of shaft 25 is driven by a motor 21 thru the intermediary of a suitable speed reducer 28 and an elevating mechanism 29 is also provided on whaft 25, whereby to permit the disposition of the agitator 24 at selective elevations in tank 5.

Elevating mechanism of this type has been illustrated and described in United States Patent No. 1,962,646 to Leland H. Logue.

In addition to the foregoing adjustment of the agitator 24 relative to the bottom of tank 5, the position of the agitator blades may also be varied.

The agitator 24 consists of blades 24a and 24b, preferably formed of angle iron with the apex at the top, disposed in spaced parallel relation with an end 30 of each blade pivotally mounted on the shaft 25. A hub or collar 39 is fixed on shaft 25 and disposed between the ends 30 of the blades 24a and 24b, and a pin 3| extends thru said hub and the ends of the blades.

A sleeve 40 on shaft 25 normally rests on hub 39 and arms 4!, pivoted to the upper end of sleeve 40 and the outer ends of blades 24a and 24b, permits changes in elevation of the said outer ends relative to hub 39.

A tightening nut or other suitable fastening at an end of pin 3| is used to hold the blades against relative movement in selective positions.

In Figure 2, the dotted line A indicates an elevated position for agitator 245 which may be effected by operation of mechanism 29. The dotted line B indicates an adjustment of blades 24a and 24b in which their outer ends are elevated with respect to their pivoted ends. These illustrations typify the various adjustments of the agitator.

A stirring agitator 35 may be carried on shaft 25, at a distance above the agitator 24 and if the tank is of suflicient depth, a plurality of stirring agitators may be employed. The function of these agitators will be explained hereinafter.

A sand relief discharge is also provided for the tank 5 and comprises an open-ended conduit 35 of restricted volume, discharging thru the tank at an elevation lower than overflow 5 and adjacent thereto. The difference in head between the discharge of conduit 35 and overflow 6 causes sands to be forced in and thru said conduit. A launder 36 is provided to receive the combined discharge of overflow B and conduit 35.

In order to control the volume of air admitted to conditioner casing 8, a plug 31 is slidably mounted on a housing 38 around shaft 12 and acts as a valve to control the flow of air thru the open end of easing 8, as shown in Figure 4.

It will be understood that the number of conditioner units and air lifts employed may vary with the type of treatment and size of the tank. For certain types of treatment one air lift and one conditioner unit would be sufficient to attain the desired results, but in most treatments a plurality of air lifts and conditioners will be required.

While only two conditioner units have been described and shown in the drawing, it is to be understood ,that any desired number may be employed in the tank. Likewise, under certain conditions of operation it will be preferable to have all the air lifts outside the tank, at other times it may be desirable to have all the air lifts in the tank, and under other conditions some may be inside and some outside, as illustrated.

In operation, feed from a suitable source of supply (not shown) may be delivered to conduits 23, or otherwise introduced into tank 5. Suitable reagents may be similarly introduced. The overflow 6 determines the liquid level when a continuous operation is employed, and when the tank is filled to the overflow level, the impellers l0 and agitators 24 and 34 are rotated.

The amount of feed delivered to the conditioner units is controlled by regulation of valves 33 and 33a, and the amount of air to be mixed with the feed is also controlled by adjustment of plugs 31. As supernatant matter forms on the surface, it is drawn thru openings I! by the suction influence of impellers l0.

The air, feed and supernatant matter is initially mixed as it passes thru the restricted opening into the flaring portion 9 of the conditioner units. The impellers l0 rotate at relatively high speed, and are shielded from descending material other than that admitted thru casing 8.

As a result, material acted on by impellers III is mixed and rapidly thrown downwardly so that it will be diffused thru the liquid body, thereby bringing the reagent in contact with a large amount of the solids in suspension.

Heavier solids in the pulp tend to settle out and stirring agitators 34 act on the settling material to maintain it in suspension. The agitator 24 has a similar function and in addition serves to move settling material to the zone of influence of air lifts 2i] and 20a, wherein it is elevated and delivered to conduits 23 for distribution in the upper portion of the tank.

The conditioned material is discharged across overflow 6 into launder 36. Sands which are not readily elevated to overflow 6 and would otherwise collect in the tank and increase the density of the pulp, are entrapped in conduit 35 and likewise discharged into launder 35.

From the foregoing, it will be apparent that the upper portion of the liquid body constitutes the treatment zone, in which the pulp is aerated, mixed with reagent and diffused thru the liquid body, and the operation repeated until substantially all the material has been acted on by the reagent, and sufficient time permitted for the same to be properly conditioned before its discharge from the tank.

Material which otherwise would be removed from the treatment. zone by settling is maintained in suspension by agitators 34 and is returned to said zone to be acted on further therein.

The lower portion of the tank constitutes a circulation zone in which material settling to the bottom, which would otherwise be removed from treatment, is agitated to keep it in suspension and is directed to the air lifts Where it is elevated, aerated and returned to the treatment zone.

The conditioner units of the apparatus are designed to permit wide variations in treatment, as both the feed supply and air supply can be varied at will. If sufficient air is provided by the aerated feed, and the supernatant matter introduced into the same, the plug 31 can be moved down to close the open upper end of casing 8. Likewise, valve can be regulated to cut off the supply of feed vllrll branch H6 or to permit any desired amount to be fed therethru.

The elevation of agitators 34 and 24 may be varied at the will of the operator, and if any increase in density of pulp is noted in the liquid body, the agitators can be raised or lowered as required to best act on the denser pulp. Likewise, it may be desirable to change the position Of. the blades 24a and 24b, as'an example, after a shut down, and these blades,may be moved to the position B, or similar positions, to prevent overloading in starting.

From the foregoing. it will be apparent that the apparatus iseflicient in operation and adapted for a variety of treatments, while being of simple and durable construction.

In the description, reference has been made to the conditioning of pulps as a part of the treat ment practiced in the milling of ores. It is to be understood that this terminology is merely illustrative, and any materials amenable to a conditioning or agitating treatment in apparatus of this general character, may be conditioned or agitated effectively by the present invent on. The term pulp is therefore used in its broadest sense and is not intended to be restricted to mineral particles in liquid suspension.

Changes and modifications may be avaled of within the spirit and scope of the invention as defined in the hereunto appended claims.

What I claim and desire to secure by Letters Patent is:

1. A conditioner or agitator comprising a tank for pulp, a conditioner element in the tank for mixing and aerating feed and partially conditioned material, an air lift for returning settled material to the conditioner element, having an inlet in the lower portion of the tank, and an agitator in the lower portion of the tank for directing settled material to the air lift inlet.

2. A conditioner or agitator comprising a tank for pulp, a conditioner element in the tank for 'mixing and aerating feed and partially conditioned material, an air lift within the tank for returning settled material to the conditioner element, having an inlet in the lower portion of the tank, and an agitator in the lower portion of the tank for directing settled material to the air lift inlet.

3. A conditioner or agitator comprising a tank for pulp, a conditioner element in the tank for mixing and aerating feed. and partially conditioned material, an air lift outside the tank for returning settled material to the conditioner element, having an inlet in the lower portion of the tank, and an agitator in the lower portion of the tank for directing settled material to the air lift inlet.

4.-A conditioner or agitator comprising a tank for pulp, a conditioner element in the tank for mixing and aerating feed and partially conditioned material, a plurality of air lifts for returning settled material to the conditioner element, each having an inlet in the lower portion of the tank, one of said air lifts being outside the tank and another being within the tank, and an agitator in the lower portion of the tank for directing settled material to the air liftinlets.

5. A conditioner or agitator comprising a tank for pulp, a conditioner element in the tank for mixing and aeratingfeedandpartially conditioned material, an upwardly ranging conduit for returning settled material to the conditioner element having an inlet in the lower portion of the tank, means for admitting a pressure gas into said conduitadjacent the inlet, and an agitator in the lower portion of the tank for directing settled material to the air lift inlet.

- 6. A conditioner or agitator comprising a tank for pulp, a conditioner element in the tank for mixing and aerating feed and partially conditioned'material, an air lift for returning settled material to the conditioner element, having an inlet in the lower portion of the tank, an agitator in the lower portion of the tank for directing settled material to the air lift inlet, and means for varyingthe elevation of said agitator relative to said inlet.

'7. A conditioner or agitator comprising a tank for pulp, a conditioner element in the tank for mixing and aerating feed and partially conditioned material, an air lift for returning settled material to the conditioner element, having an inlet in the lower portion of the tank, and an agitator composed of a plurality of blades disposed in the lower portion of the tank for directing settled material to the air lift inlet, the said blades being adjustable for their disposition in selective planes in the bottom of the tank.

8. A conditioner oi agitator comprising a tank for pulp havinga discharge outlet determining a liquid level therein, a conditioner element in the tank having an inlet for admission of supernatant matter at the approximate liquid level in the tank, an air lift for returning settled material to the conditioner element, having an inlet in the lower portion of the tank, a rotary impeller in the conditioner element for mixing and discharging the recirculating materials, and an agitator in the lower portion of the tank for directing settled material to the air lift inlet.

9. A conditioner or agitator comprising a tank for pulp having a discharge outlet determining a liquid level therein, a conditioner element in the tank for mixing and aerating partially conditioned material, an air lift for returning settled material to the conditioner element, having an inlet in the lower portion of the tank, an agitator in the lower portion of the tank for directing settled material to the air lift inlet, and a second agitator intermediate the overflow and the bottom of the tank for acting on material settling in the tank.

10. In apparatus for the treatment of solids in liquid suspension, a tank having a discharge outlet determining a liquid level therein, and a conduit of restricted volume, having an inlet in the lower portion of. the tank and having a discharge from the tank above'said inlet and at a lower elevation than the liquid level determined by the discharge outlet, whereby solids in liquid are discharged thru the conduit by hydrostatic pressure in the tank.

11. A conditioner or agitator comprising a tank having means determining a liquid level therein, a conditioner element in the tank comprising a hollow body having one of its ends above the liquid level and its opposite end terminating in a flaring portion within the liquid body in the tank, there being a restlicted passage between the hollow body and the flaring portion, the hollow body having a feed inlet, and an opening for admission of material from the tank adjacent its liquid level, a rotary shaft extending thru the hollow body, an impeller on the shaft in the flaring portion for acting on material moving thru the restricted passage, .and a plug slidably mounted on the shaft adjacent the upper end of the hollow body and movable relative thereto to control the admission of air therethru.

12. In a conditioner or agitator comprising a tank for pulp, an air lift for returning settled matter to the upper portion of the tank, having an inlet in the lower portion of the tank, an agitator in the lower portion of the tank for directing settled material to the air lift inlet,

and means for varying the elevation of said agitator relative to said inlet.

13. In apparatus of the character described, a conditioner unit comprising a hollow body mounted in a tank with an open end extending above a liquid level in the tank and its opposite end submerged and terminating in a flaring portion,

the body having an inlet for supernatant matter conduit projecting at a side thereof for con nection with a recirculation conduit, there being a restricted passage in the body into the flaring portion, and a rotary impeller in the flaring portion for acting on matter delivered to the hollow body.

15. In apparatus of the character described, a conditioner unit comprising a hollow body mounted in a tank with an open end extending above a liquid level in the tank and its opposite end submerged and terminating in a flaring portion, the body having an inlet for supernatant matter intermediate its ends and having a branch conduit projecting at a side thereof for connection with a recirculation conduit, a valve at the open end of the hollow body for regulating the intake of air therethrough, and a rotary impeller in the flaring portion for acting on matter delivered to the hollow body.

' ARTHUR C. DAMAN. 

